Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
1da177e4 LT |
48 | #include <linux/notifier.h> |
49 | #include <linux/security.h> | |
50 | #include <linux/jhash.h> | |
51 | #include <linux/jiffies.h> | |
52 | #include <linux/random.h> | |
53 | #include <linux/bitops.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/types.h> | |
54e0f520 | 56 | #include <linux/audit.h> |
af65bdfc | 57 | #include <linux/mutex.h> |
54e0f520 | 58 | |
457c4cbc | 59 | #include <net/net_namespace.h> |
1da177e4 LT |
60 | #include <net/sock.h> |
61 | #include <net/scm.h> | |
82ace47a | 62 | #include <net/netlink.h> |
1da177e4 | 63 | |
f7fa9b10 | 64 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
b4ff4f04 | 65 | #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) |
1da177e4 LT |
66 | |
67 | struct netlink_sock { | |
68 | /* struct sock has to be the first member of netlink_sock */ | |
69 | struct sock sk; | |
70 | u32 pid; | |
1da177e4 | 71 | u32 dst_pid; |
d629b836 | 72 | u32 dst_group; |
f7fa9b10 PM |
73 | u32 flags; |
74 | u32 subscriptions; | |
75 | u32 ngroups; | |
76 | unsigned long *groups; | |
1da177e4 LT |
77 | unsigned long state; |
78 | wait_queue_head_t wait; | |
79 | struct netlink_callback *cb; | |
af65bdfc PM |
80 | struct mutex *cb_mutex; |
81 | struct mutex cb_def_mutex; | |
cd40b7d3 | 82 | void (*netlink_rcv)(struct sk_buff *skb); |
77247bbb | 83 | struct module *module; |
1da177e4 LT |
84 | }; |
85 | ||
6c04bb18 JB |
86 | struct listeners_rcu_head { |
87 | struct rcu_head rcu_head; | |
88 | void *ptr; | |
89 | }; | |
90 | ||
77247bbb | 91 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 92 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 93 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
38938bfe | 94 | #define NETLINK_RECV_NO_ENOBUFS 0x8 |
77247bbb | 95 | |
1da177e4 LT |
96 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
97 | { | |
32b21e03 | 98 | return container_of(sk, struct netlink_sock, sk); |
1da177e4 LT |
99 | } |
100 | ||
aed81560 DL |
101 | static inline int netlink_is_kernel(struct sock *sk) |
102 | { | |
103 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
104 | } | |
105 | ||
1da177e4 LT |
106 | struct nl_pid_hash { |
107 | struct hlist_head *table; | |
108 | unsigned long rehash_time; | |
109 | ||
110 | unsigned int mask; | |
111 | unsigned int shift; | |
112 | ||
113 | unsigned int entries; | |
114 | unsigned int max_shift; | |
115 | ||
116 | u32 rnd; | |
117 | }; | |
118 | ||
119 | struct netlink_table { | |
120 | struct nl_pid_hash hash; | |
121 | struct hlist_head mc_list; | |
4277a083 | 122 | unsigned long *listeners; |
1da177e4 | 123 | unsigned int nl_nonroot; |
f7fa9b10 | 124 | unsigned int groups; |
af65bdfc | 125 | struct mutex *cb_mutex; |
77247bbb | 126 | struct module *module; |
ab33a171 | 127 | int registered; |
1da177e4 LT |
128 | }; |
129 | ||
130 | static struct netlink_table *nl_table; | |
131 | ||
132 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
133 | ||
134 | static int netlink_dump(struct sock *sk); | |
135 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
136 | ||
137 | static DEFINE_RWLOCK(nl_table_lock); | |
138 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
139 | ||
e041c683 | 140 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 141 | |
d629b836 PM |
142 | static u32 netlink_group_mask(u32 group) |
143 | { | |
144 | return group ? 1 << (group - 1) : 0; | |
145 | } | |
146 | ||
1da177e4 LT |
147 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
148 | { | |
149 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
150 | } | |
151 | ||
152 | static void netlink_sock_destruct(struct sock *sk) | |
153 | { | |
3f660d66 HX |
154 | struct netlink_sock *nlk = nlk_sk(sk); |
155 | ||
3f660d66 HX |
156 | if (nlk->cb) { |
157 | if (nlk->cb->done) | |
158 | nlk->cb->done(nlk->cb); | |
159 | netlink_destroy_callback(nlk->cb); | |
160 | } | |
161 | ||
1da177e4 LT |
162 | skb_queue_purge(&sk->sk_receive_queue); |
163 | ||
164 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 165 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
166 | return; |
167 | } | |
547b792c IJ |
168 | |
169 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
170 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
171 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
172 | } |
173 | ||
6ac552fd PM |
174 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
175 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
176 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
177 | * this, _but_ remember, it adds useless work on UP machines. | |
178 | */ | |
179 | ||
d136f1bd | 180 | void netlink_table_grab(void) |
9a429c49 | 181 | __acquires(nl_table_lock) |
1da177e4 | 182 | { |
d136f1bd JB |
183 | might_sleep(); |
184 | ||
6abd219c | 185 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
186 | |
187 | if (atomic_read(&nl_table_users)) { | |
188 | DECLARE_WAITQUEUE(wait, current); | |
189 | ||
190 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 191 | for (;;) { |
1da177e4 LT |
192 | set_current_state(TASK_UNINTERRUPTIBLE); |
193 | if (atomic_read(&nl_table_users) == 0) | |
194 | break; | |
6abd219c | 195 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 196 | schedule(); |
6abd219c | 197 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
198 | } |
199 | ||
200 | __set_current_state(TASK_RUNNING); | |
201 | remove_wait_queue(&nl_table_wait, &wait); | |
202 | } | |
203 | } | |
204 | ||
d136f1bd | 205 | void netlink_table_ungrab(void) |
9a429c49 | 206 | __releases(nl_table_lock) |
1da177e4 | 207 | { |
6abd219c | 208 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
209 | wake_up(&nl_table_wait); |
210 | } | |
211 | ||
6ac552fd | 212 | static inline void |
1da177e4 LT |
213 | netlink_lock_table(void) |
214 | { | |
215 | /* read_lock() synchronizes us to netlink_table_grab */ | |
216 | ||
217 | read_lock(&nl_table_lock); | |
218 | atomic_inc(&nl_table_users); | |
219 | read_unlock(&nl_table_lock); | |
220 | } | |
221 | ||
6ac552fd | 222 | static inline void |
1da177e4 LT |
223 | netlink_unlock_table(void) |
224 | { | |
225 | if (atomic_dec_and_test(&nl_table_users)) | |
226 | wake_up(&nl_table_wait); | |
227 | } | |
228 | ||
6ac552fd PM |
229 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
230 | u32 pid) | |
1da177e4 LT |
231 | { |
232 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
233 | struct hlist_head *head; | |
234 | struct sock *sk; | |
235 | struct hlist_node *node; | |
236 | ||
237 | read_lock(&nl_table_lock); | |
238 | head = nl_pid_hashfn(hash, pid); | |
239 | sk_for_each(sk, node, head) { | |
878628fb | 240 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
241 | sock_hold(sk); |
242 | goto found; | |
243 | } | |
244 | } | |
245 | sk = NULL; | |
246 | found: | |
247 | read_unlock(&nl_table_lock); | |
248 | return sk; | |
249 | } | |
250 | ||
ea72912c | 251 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
252 | { |
253 | if (size <= PAGE_SIZE) | |
ea72912c | 254 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
255 | else |
256 | return (struct hlist_head *) | |
ea72912c ED |
257 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
258 | get_order(size)); | |
1da177e4 LT |
259 | } |
260 | ||
261 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
262 | { | |
263 | if (size <= PAGE_SIZE) | |
264 | kfree(table); | |
265 | else | |
266 | free_pages((unsigned long)table, get_order(size)); | |
267 | } | |
268 | ||
269 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
270 | { | |
271 | unsigned int omask, mask, shift; | |
272 | size_t osize, size; | |
273 | struct hlist_head *otable, *table; | |
274 | int i; | |
275 | ||
276 | omask = mask = hash->mask; | |
277 | osize = size = (mask + 1) * sizeof(*table); | |
278 | shift = hash->shift; | |
279 | ||
280 | if (grow) { | |
281 | if (++shift > hash->max_shift) | |
282 | return 0; | |
283 | mask = mask * 2 + 1; | |
284 | size *= 2; | |
285 | } | |
286 | ||
ea72912c | 287 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
288 | if (!table) |
289 | return 0; | |
290 | ||
1da177e4 LT |
291 | otable = hash->table; |
292 | hash->table = table; | |
293 | hash->mask = mask; | |
294 | hash->shift = shift; | |
295 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
296 | ||
297 | for (i = 0; i <= omask; i++) { | |
298 | struct sock *sk; | |
299 | struct hlist_node *node, *tmp; | |
300 | ||
301 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
302 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
303 | } | |
304 | ||
305 | nl_pid_hash_free(otable, osize); | |
306 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
307 | return 1; | |
308 | } | |
309 | ||
310 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
311 | { | |
312 | int avg = hash->entries >> hash->shift; | |
313 | ||
314 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
315 | return 1; | |
316 | ||
317 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
318 | nl_pid_hash_rehash(hash, 0); | |
319 | return 1; | |
320 | } | |
321 | ||
322 | return 0; | |
323 | } | |
324 | ||
90ddc4f0 | 325 | static const struct proto_ops netlink_ops; |
1da177e4 | 326 | |
4277a083 PM |
327 | static void |
328 | netlink_update_listeners(struct sock *sk) | |
329 | { | |
330 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
331 | struct hlist_node *node; | |
332 | unsigned long mask; | |
333 | unsigned int i; | |
334 | ||
b4ff4f04 | 335 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 336 | mask = 0; |
b4ff4f04 JB |
337 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
338 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
339 | mask |= nlk_sk(sk)->groups[i]; | |
340 | } | |
4277a083 PM |
341 | tbl->listeners[i] = mask; |
342 | } | |
343 | /* this function is only called with the netlink table "grabbed", which | |
344 | * makes sure updates are visible before bind or setsockopt return. */ | |
345 | } | |
346 | ||
b4b51029 | 347 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
348 | { |
349 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
350 | struct hlist_head *head; | |
351 | int err = -EADDRINUSE; | |
352 | struct sock *osk; | |
353 | struct hlist_node *node; | |
354 | int len; | |
355 | ||
356 | netlink_table_grab(); | |
357 | head = nl_pid_hashfn(hash, pid); | |
358 | len = 0; | |
359 | sk_for_each(osk, node, head) { | |
878628fb | 360 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
361 | break; |
362 | len++; | |
363 | } | |
364 | if (node) | |
365 | goto err; | |
366 | ||
367 | err = -EBUSY; | |
368 | if (nlk_sk(sk)->pid) | |
369 | goto err; | |
370 | ||
371 | err = -ENOMEM; | |
372 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
373 | goto err; | |
374 | ||
375 | if (len && nl_pid_hash_dilute(hash, len)) | |
376 | head = nl_pid_hashfn(hash, pid); | |
377 | hash->entries++; | |
378 | nlk_sk(sk)->pid = pid; | |
379 | sk_add_node(sk, head); | |
380 | err = 0; | |
381 | ||
382 | err: | |
383 | netlink_table_ungrab(); | |
384 | return err; | |
385 | } | |
386 | ||
387 | static void netlink_remove(struct sock *sk) | |
388 | { | |
389 | netlink_table_grab(); | |
d470e3b4 DM |
390 | if (sk_del_node_init(sk)) |
391 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 392 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
393 | __sk_del_bind_node(sk); |
394 | netlink_table_ungrab(); | |
395 | } | |
396 | ||
397 | static struct proto netlink_proto = { | |
398 | .name = "NETLINK", | |
399 | .owner = THIS_MODULE, | |
400 | .obj_size = sizeof(struct netlink_sock), | |
401 | }; | |
402 | ||
1b8d7ae4 EB |
403 | static int __netlink_create(struct net *net, struct socket *sock, |
404 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
405 | { |
406 | struct sock *sk; | |
407 | struct netlink_sock *nlk; | |
ab33a171 PM |
408 | |
409 | sock->ops = &netlink_ops; | |
410 | ||
6257ff21 | 411 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
412 | if (!sk) |
413 | return -ENOMEM; | |
414 | ||
415 | sock_init_data(sock, sk); | |
416 | ||
417 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
418 | if (cb_mutex) |
419 | nlk->cb_mutex = cb_mutex; | |
420 | else { | |
421 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
422 | mutex_init(nlk->cb_mutex); | |
423 | } | |
ab33a171 PM |
424 | init_waitqueue_head(&nlk->wait); |
425 | ||
426 | sk->sk_destruct = netlink_sock_destruct; | |
427 | sk->sk_protocol = protocol; | |
428 | return 0; | |
429 | } | |
430 | ||
3f378b68 EP |
431 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
432 | int kern) | |
ab33a171 PM |
433 | { |
434 | struct module *module = NULL; | |
af65bdfc | 435 | struct mutex *cb_mutex; |
f7fa9b10 | 436 | struct netlink_sock *nlk; |
ab33a171 | 437 | int err = 0; |
1da177e4 LT |
438 | |
439 | sock->state = SS_UNCONNECTED; | |
440 | ||
441 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
442 | return -ESOCKTNOSUPPORT; | |
443 | ||
6ac552fd | 444 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
445 | return -EPROTONOSUPPORT; |
446 | ||
77247bbb | 447 | netlink_lock_table(); |
95a5afca | 448 | #ifdef CONFIG_MODULES |
ab33a171 | 449 | if (!nl_table[protocol].registered) { |
77247bbb | 450 | netlink_unlock_table(); |
4fdb3bb7 | 451 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 452 | netlink_lock_table(); |
4fdb3bb7 | 453 | } |
ab33a171 PM |
454 | #endif |
455 | if (nl_table[protocol].registered && | |
456 | try_module_get(nl_table[protocol].module)) | |
457 | module = nl_table[protocol].module; | |
af65bdfc | 458 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 459 | netlink_unlock_table(); |
4fdb3bb7 | 460 | |
6ac552fd PM |
461 | err = __netlink_create(net, sock, cb_mutex, protocol); |
462 | if (err < 0) | |
f7fa9b10 PM |
463 | goto out_module; |
464 | ||
6f756a8c | 465 | local_bh_disable(); |
c1fd3b94 | 466 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
467 | local_bh_enable(); |
468 | ||
f7fa9b10 | 469 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 470 | nlk->module = module; |
ab33a171 PM |
471 | out: |
472 | return err; | |
1da177e4 | 473 | |
ab33a171 PM |
474 | out_module: |
475 | module_put(module); | |
476 | goto out; | |
1da177e4 LT |
477 | } |
478 | ||
479 | static int netlink_release(struct socket *sock) | |
480 | { | |
481 | struct sock *sk = sock->sk; | |
482 | struct netlink_sock *nlk; | |
483 | ||
484 | if (!sk) | |
485 | return 0; | |
486 | ||
487 | netlink_remove(sk); | |
ac57b3a9 | 488 | sock_orphan(sk); |
1da177e4 LT |
489 | nlk = nlk_sk(sk); |
490 | ||
3f660d66 HX |
491 | /* |
492 | * OK. Socket is unlinked, any packets that arrive now | |
493 | * will be purged. | |
494 | */ | |
1da177e4 | 495 | |
1da177e4 LT |
496 | sock->sk = NULL; |
497 | wake_up_interruptible_all(&nlk->wait); | |
498 | ||
499 | skb_queue_purge(&sk->sk_write_queue); | |
500 | ||
649300b9 | 501 | if (nlk->pid) { |
1da177e4 | 502 | struct netlink_notify n = { |
3b1e0a65 | 503 | .net = sock_net(sk), |
1da177e4 LT |
504 | .protocol = sk->sk_protocol, |
505 | .pid = nlk->pid, | |
506 | }; | |
e041c683 AS |
507 | atomic_notifier_call_chain(&netlink_chain, |
508 | NETLINK_URELEASE, &n); | |
746fac4d | 509 | } |
4fdb3bb7 | 510 | |
5e7c001c | 511 | module_put(nlk->module); |
4fdb3bb7 | 512 | |
4277a083 | 513 | netlink_table_grab(); |
aed81560 | 514 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
515 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
516 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
517 | kfree(nl_table[sk->sk_protocol].listeners); | |
518 | nl_table[sk->sk_protocol].module = NULL; | |
519 | nl_table[sk->sk_protocol].registered = 0; | |
520 | } | |
4277a083 PM |
521 | } else if (nlk->subscriptions) |
522 | netlink_update_listeners(sk); | |
523 | netlink_table_ungrab(); | |
77247bbb | 524 | |
f7fa9b10 PM |
525 | kfree(nlk->groups); |
526 | nlk->groups = NULL; | |
527 | ||
3755810c | 528 | local_bh_disable(); |
c1fd3b94 | 529 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 530 | local_bh_enable(); |
1da177e4 LT |
531 | sock_put(sk); |
532 | return 0; | |
533 | } | |
534 | ||
535 | static int netlink_autobind(struct socket *sock) | |
536 | { | |
537 | struct sock *sk = sock->sk; | |
3b1e0a65 | 538 | struct net *net = sock_net(sk); |
1da177e4 LT |
539 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
540 | struct hlist_head *head; | |
541 | struct sock *osk; | |
542 | struct hlist_node *node; | |
c27bd492 | 543 | s32 pid = current->tgid; |
1da177e4 LT |
544 | int err; |
545 | static s32 rover = -4097; | |
546 | ||
547 | retry: | |
548 | cond_resched(); | |
549 | netlink_table_grab(); | |
550 | head = nl_pid_hashfn(hash, pid); | |
551 | sk_for_each(osk, node, head) { | |
878628fb | 552 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 553 | continue; |
1da177e4 LT |
554 | if (nlk_sk(osk)->pid == pid) { |
555 | /* Bind collision, search negative pid values. */ | |
556 | pid = rover--; | |
557 | if (rover > -4097) | |
558 | rover = -4097; | |
559 | netlink_table_ungrab(); | |
560 | goto retry; | |
561 | } | |
562 | } | |
563 | netlink_table_ungrab(); | |
564 | ||
b4b51029 | 565 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
566 | if (err == -EADDRINUSE) |
567 | goto retry; | |
d470e3b4 DM |
568 | |
569 | /* If 2 threads race to autobind, that is fine. */ | |
570 | if (err == -EBUSY) | |
571 | err = 0; | |
572 | ||
573 | return err; | |
1da177e4 LT |
574 | } |
575 | ||
746fac4d YH |
576 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
577 | { | |
1da177e4 LT |
578 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
579 | capable(CAP_NET_ADMIN); | |
746fac4d | 580 | } |
1da177e4 | 581 | |
f7fa9b10 PM |
582 | static void |
583 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
584 | { | |
585 | struct netlink_sock *nlk = nlk_sk(sk); | |
586 | ||
587 | if (nlk->subscriptions && !subscriptions) | |
588 | __sk_del_bind_node(sk); | |
589 | else if (!nlk->subscriptions && subscriptions) | |
590 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
591 | nlk->subscriptions = subscriptions; | |
592 | } | |
593 | ||
b4ff4f04 | 594 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
595 | { |
596 | struct netlink_sock *nlk = nlk_sk(sk); | |
597 | unsigned int groups; | |
b4ff4f04 | 598 | unsigned long *new_groups; |
513c2500 PM |
599 | int err = 0; |
600 | ||
b4ff4f04 JB |
601 | netlink_table_grab(); |
602 | ||
513c2500 | 603 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 604 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 605 | err = -ENOENT; |
b4ff4f04 JB |
606 | goto out_unlock; |
607 | } | |
513c2500 | 608 | |
b4ff4f04 JB |
609 | if (nlk->ngroups >= groups) |
610 | goto out_unlock; | |
513c2500 | 611 | |
b4ff4f04 JB |
612 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
613 | if (new_groups == NULL) { | |
614 | err = -ENOMEM; | |
615 | goto out_unlock; | |
616 | } | |
6ac552fd | 617 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
618 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
619 | ||
620 | nlk->groups = new_groups; | |
513c2500 | 621 | nlk->ngroups = groups; |
b4ff4f04 JB |
622 | out_unlock: |
623 | netlink_table_ungrab(); | |
624 | return err; | |
513c2500 PM |
625 | } |
626 | ||
6ac552fd PM |
627 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
628 | int addr_len) | |
1da177e4 LT |
629 | { |
630 | struct sock *sk = sock->sk; | |
3b1e0a65 | 631 | struct net *net = sock_net(sk); |
1da177e4 LT |
632 | struct netlink_sock *nlk = nlk_sk(sk); |
633 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
634 | int err; | |
746fac4d | 635 | |
1da177e4 LT |
636 | if (nladdr->nl_family != AF_NETLINK) |
637 | return -EINVAL; | |
638 | ||
639 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
640 | if (nladdr->nl_groups) { |
641 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
642 | return -EPERM; | |
b4ff4f04 JB |
643 | err = netlink_realloc_groups(sk); |
644 | if (err) | |
645 | return err; | |
513c2500 | 646 | } |
1da177e4 LT |
647 | |
648 | if (nlk->pid) { | |
649 | if (nladdr->nl_pid != nlk->pid) | |
650 | return -EINVAL; | |
651 | } else { | |
652 | err = nladdr->nl_pid ? | |
b4b51029 | 653 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
654 | netlink_autobind(sock); |
655 | if (err) | |
656 | return err; | |
657 | } | |
658 | ||
513c2500 | 659 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
660 | return 0; |
661 | ||
662 | netlink_table_grab(); | |
f7fa9b10 | 663 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
664 | hweight32(nladdr->nl_groups) - |
665 | hweight32(nlk->groups[0])); | |
666 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 667 | netlink_update_listeners(sk); |
1da177e4 LT |
668 | netlink_table_ungrab(); |
669 | ||
670 | return 0; | |
671 | } | |
672 | ||
673 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
674 | int alen, int flags) | |
675 | { | |
676 | int err = 0; | |
677 | struct sock *sk = sock->sk; | |
678 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 679 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
680 | |
681 | if (addr->sa_family == AF_UNSPEC) { | |
682 | sk->sk_state = NETLINK_UNCONNECTED; | |
683 | nlk->dst_pid = 0; | |
d629b836 | 684 | nlk->dst_group = 0; |
1da177e4 LT |
685 | return 0; |
686 | } | |
687 | if (addr->sa_family != AF_NETLINK) | |
688 | return -EINVAL; | |
689 | ||
690 | /* Only superuser is allowed to send multicasts */ | |
691 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
692 | return -EPERM; | |
693 | ||
694 | if (!nlk->pid) | |
695 | err = netlink_autobind(sock); | |
696 | ||
697 | if (err == 0) { | |
698 | sk->sk_state = NETLINK_CONNECTED; | |
699 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 700 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
701 | } |
702 | ||
703 | return err; | |
704 | } | |
705 | ||
6ac552fd PM |
706 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
707 | int *addr_len, int peer) | |
1da177e4 LT |
708 | { |
709 | struct sock *sk = sock->sk; | |
710 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 711 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 712 | |
1da177e4 LT |
713 | nladdr->nl_family = AF_NETLINK; |
714 | nladdr->nl_pad = 0; | |
715 | *addr_len = sizeof(*nladdr); | |
716 | ||
717 | if (peer) { | |
718 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 719 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
720 | } else { |
721 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 722 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
723 | } |
724 | return 0; | |
725 | } | |
726 | ||
727 | static void netlink_overrun(struct sock *sk) | |
728 | { | |
38938bfe PNA |
729 | struct netlink_sock *nlk = nlk_sk(sk); |
730 | ||
731 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
732 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
733 | sk->sk_err = ENOBUFS; | |
734 | sk->sk_error_report(sk); | |
735 | } | |
1da177e4 | 736 | } |
38938bfe | 737 | atomic_inc(&sk->sk_drops); |
1da177e4 LT |
738 | } |
739 | ||
740 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
741 | { | |
1da177e4 LT |
742 | struct sock *sock; |
743 | struct netlink_sock *nlk; | |
744 | ||
3b1e0a65 | 745 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); |
1da177e4 LT |
746 | if (!sock) |
747 | return ERR_PTR(-ECONNREFUSED); | |
748 | ||
749 | /* Don't bother queuing skb if kernel socket has no input function */ | |
750 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
751 | if (sock->sk_state == NETLINK_CONNECTED && |
752 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
753 | sock_put(sock); |
754 | return ERR_PTR(-ECONNREFUSED); | |
755 | } | |
756 | return sock; | |
757 | } | |
758 | ||
759 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
760 | { | |
6db5fc5d | 761 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
762 | struct sock *sock; |
763 | ||
764 | if (!S_ISSOCK(inode->i_mode)) | |
765 | return ERR_PTR(-ENOTSOCK); | |
766 | ||
767 | sock = SOCKET_I(inode)->sk; | |
768 | if (sock->sk_family != AF_NETLINK) | |
769 | return ERR_PTR(-EINVAL); | |
770 | ||
771 | sock_hold(sock); | |
772 | return sock; | |
773 | } | |
774 | ||
775 | /* | |
776 | * Attach a skb to a netlink socket. | |
777 | * The caller must hold a reference to the destination socket. On error, the | |
778 | * reference is dropped. The skb is not send to the destination, just all | |
779 | * all error checks are performed and memory in the queue is reserved. | |
780 | * Return values: | |
781 | * < 0: error. skb freed, reference to sock dropped. | |
782 | * 0: continue | |
783 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
784 | */ | |
9457afee | 785 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 786 | long *timeo, struct sock *ssk) |
1da177e4 LT |
787 | { |
788 | struct netlink_sock *nlk; | |
789 | ||
790 | nlk = nlk_sk(sk); | |
791 | ||
792 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
793 | test_bit(0, &nlk->state)) { | |
794 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 795 | if (!*timeo) { |
aed81560 | 796 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
797 | netlink_overrun(sk); |
798 | sock_put(sk); | |
799 | kfree_skb(skb); | |
800 | return -EAGAIN; | |
801 | } | |
802 | ||
803 | __set_current_state(TASK_INTERRUPTIBLE); | |
804 | add_wait_queue(&nlk->wait, &wait); | |
805 | ||
806 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
807 | test_bit(0, &nlk->state)) && | |
808 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 809 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
810 | |
811 | __set_current_state(TASK_RUNNING); | |
812 | remove_wait_queue(&nlk->wait, &wait); | |
813 | sock_put(sk); | |
814 | ||
815 | if (signal_pending(current)) { | |
816 | kfree_skb(skb); | |
c3d8d1e3 | 817 | return sock_intr_errno(*timeo); |
1da177e4 LT |
818 | } |
819 | return 1; | |
820 | } | |
821 | skb_set_owner_r(skb, sk); | |
822 | return 0; | |
823 | } | |
824 | ||
7ee015e0 | 825 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 826 | { |
1da177e4 LT |
827 | int len = skb->len; |
828 | ||
1da177e4 LT |
829 | skb_queue_tail(&sk->sk_receive_queue, skb); |
830 | sk->sk_data_ready(sk, len); | |
831 | sock_put(sk); | |
832 | return len; | |
833 | } | |
834 | ||
835 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
836 | { | |
837 | kfree_skb(skb); | |
838 | sock_put(sk); | |
839 | } | |
840 | ||
37da647d | 841 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 842 | gfp_t allocation) |
1da177e4 LT |
843 | { |
844 | int delta; | |
845 | ||
846 | skb_orphan(skb); | |
847 | ||
4305b541 | 848 | delta = skb->end - skb->tail; |
1da177e4 LT |
849 | if (delta * 2 < skb->truesize) |
850 | return skb; | |
851 | ||
852 | if (skb_shared(skb)) { | |
853 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
854 | if (!nskb) | |
855 | return skb; | |
856 | kfree_skb(skb); | |
857 | skb = nskb; | |
858 | } | |
859 | ||
860 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
861 | skb->truesize -= delta; | |
862 | ||
863 | return skb; | |
864 | } | |
865 | ||
cd40b7d3 DL |
866 | static inline void netlink_rcv_wake(struct sock *sk) |
867 | { | |
868 | struct netlink_sock *nlk = nlk_sk(sk); | |
869 | ||
870 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
871 | clear_bit(0, &nlk->state); | |
872 | if (!test_bit(0, &nlk->state)) | |
873 | wake_up_interruptible(&nlk->wait); | |
874 | } | |
875 | ||
876 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
877 | { | |
878 | int ret; | |
879 | struct netlink_sock *nlk = nlk_sk(sk); | |
880 | ||
881 | ret = -ECONNREFUSED; | |
882 | if (nlk->netlink_rcv != NULL) { | |
883 | ret = skb->len; | |
884 | skb_set_owner_r(skb, sk); | |
885 | nlk->netlink_rcv(skb); | |
886 | } | |
887 | kfree_skb(skb); | |
888 | sock_put(sk); | |
889 | return ret; | |
890 | } | |
891 | ||
892 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
893 | u32 pid, int nonblock) | |
1da177e4 LT |
894 | { |
895 | struct sock *sk; | |
896 | int err; | |
897 | long timeo; | |
898 | ||
899 | skb = netlink_trim(skb, gfp_any()); | |
900 | ||
901 | timeo = sock_sndtimeo(ssk, nonblock); | |
902 | retry: | |
903 | sk = netlink_getsockbypid(ssk, pid); | |
904 | if (IS_ERR(sk)) { | |
905 | kfree_skb(skb); | |
906 | return PTR_ERR(sk); | |
907 | } | |
cd40b7d3 DL |
908 | if (netlink_is_kernel(sk)) |
909 | return netlink_unicast_kernel(sk, skb); | |
910 | ||
b1153f29 | 911 | if (sk_filter(sk, skb)) { |
84874607 | 912 | err = skb->len; |
b1153f29 SH |
913 | kfree_skb(skb); |
914 | sock_put(sk); | |
915 | return err; | |
916 | } | |
917 | ||
9457afee | 918 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
919 | if (err == 1) |
920 | goto retry; | |
921 | if (err) | |
922 | return err; | |
923 | ||
7ee015e0 | 924 | return netlink_sendskb(sk, skb); |
1da177e4 | 925 | } |
6ac552fd | 926 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 927 | |
4277a083 PM |
928 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
929 | { | |
930 | int res = 0; | |
b4ff4f04 | 931 | unsigned long *listeners; |
4277a083 | 932 | |
aed81560 | 933 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
934 | |
935 | rcu_read_lock(); | |
936 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
937 | ||
4277a083 | 938 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
939 | res = test_bit(group - 1, listeners); |
940 | ||
941 | rcu_read_unlock(); | |
942 | ||
4277a083 PM |
943 | return res; |
944 | } | |
945 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
946 | ||
6ac552fd PM |
947 | static inline int netlink_broadcast_deliver(struct sock *sk, |
948 | struct sk_buff *skb) | |
1da177e4 LT |
949 | { |
950 | struct netlink_sock *nlk = nlk_sk(sk); | |
951 | ||
952 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
953 | !test_bit(0, &nlk->state)) { | |
954 | skb_set_owner_r(skb, sk); | |
955 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
956 | sk->sk_data_ready(sk, skb->len); | |
957 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
958 | } | |
959 | return -1; | |
960 | } | |
961 | ||
962 | struct netlink_broadcast_data { | |
963 | struct sock *exclude_sk; | |
b4b51029 | 964 | struct net *net; |
1da177e4 LT |
965 | u32 pid; |
966 | u32 group; | |
967 | int failure; | |
ff491a73 | 968 | int delivery_failure; |
1da177e4 LT |
969 | int congested; |
970 | int delivered; | |
7d877f3b | 971 | gfp_t allocation; |
1da177e4 LT |
972 | struct sk_buff *skb, *skb2; |
973 | }; | |
974 | ||
975 | static inline int do_one_broadcast(struct sock *sk, | |
976 | struct netlink_broadcast_data *p) | |
977 | { | |
978 | struct netlink_sock *nlk = nlk_sk(sk); | |
979 | int val; | |
980 | ||
981 | if (p->exclude_sk == sk) | |
982 | goto out; | |
983 | ||
f7fa9b10 PM |
984 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
985 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
986 | goto out; |
987 | ||
878628fb | 988 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
989 | goto out; |
990 | ||
1da177e4 LT |
991 | if (p->failure) { |
992 | netlink_overrun(sk); | |
993 | goto out; | |
994 | } | |
995 | ||
996 | sock_hold(sk); | |
997 | if (p->skb2 == NULL) { | |
68acc024 | 998 | if (skb_shared(p->skb)) { |
1da177e4 LT |
999 | p->skb2 = skb_clone(p->skb, p->allocation); |
1000 | } else { | |
68acc024 TC |
1001 | p->skb2 = skb_get(p->skb); |
1002 | /* | |
1003 | * skb ownership may have been set when | |
1004 | * delivered to a previous socket. | |
1005 | */ | |
1006 | skb_orphan(p->skb2); | |
1da177e4 LT |
1007 | } |
1008 | } | |
1009 | if (p->skb2 == NULL) { | |
1010 | netlink_overrun(sk); | |
1011 | /* Clone failed. Notify ALL listeners. */ | |
1012 | p->failure = 1; | |
be0c22a4 PNA |
1013 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1014 | p->delivery_failure = 1; | |
b1153f29 SH |
1015 | } else if (sk_filter(sk, p->skb2)) { |
1016 | kfree_skb(p->skb2); | |
1017 | p->skb2 = NULL; | |
1da177e4 LT |
1018 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1019 | netlink_overrun(sk); | |
be0c22a4 PNA |
1020 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1021 | p->delivery_failure = 1; | |
1da177e4 LT |
1022 | } else { |
1023 | p->congested |= val; | |
1024 | p->delivered = 1; | |
1025 | p->skb2 = NULL; | |
1026 | } | |
1027 | sock_put(sk); | |
1028 | ||
1029 | out: | |
1030 | return 0; | |
1031 | } | |
1032 | ||
1033 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 1034 | u32 group, gfp_t allocation) |
1da177e4 | 1035 | { |
3b1e0a65 | 1036 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1037 | struct netlink_broadcast_data info; |
1038 | struct hlist_node *node; | |
1039 | struct sock *sk; | |
1040 | ||
1041 | skb = netlink_trim(skb, allocation); | |
1042 | ||
1043 | info.exclude_sk = ssk; | |
b4b51029 | 1044 | info.net = net; |
1da177e4 LT |
1045 | info.pid = pid; |
1046 | info.group = group; | |
1047 | info.failure = 0; | |
ff491a73 | 1048 | info.delivery_failure = 0; |
1da177e4 LT |
1049 | info.congested = 0; |
1050 | info.delivered = 0; | |
1051 | info.allocation = allocation; | |
1052 | info.skb = skb; | |
1053 | info.skb2 = NULL; | |
1054 | ||
1055 | /* While we sleep in clone, do not allow to change socket list */ | |
1056 | ||
1057 | netlink_lock_table(); | |
1058 | ||
1059 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1060 | do_one_broadcast(sk, &info); | |
1061 | ||
aa1c6a6f TC |
1062 | kfree_skb(skb); |
1063 | ||
1da177e4 LT |
1064 | netlink_unlock_table(); |
1065 | ||
91744f65 | 1066 | kfree_skb(info.skb2); |
1da177e4 | 1067 | |
be0c22a4 | 1068 | if (info.delivery_failure) |
ff491a73 PNA |
1069 | return -ENOBUFS; |
1070 | ||
1da177e4 LT |
1071 | if (info.delivered) { |
1072 | if (info.congested && (allocation & __GFP_WAIT)) | |
1073 | yield(); | |
1074 | return 0; | |
1075 | } | |
1da177e4 LT |
1076 | return -ESRCH; |
1077 | } | |
6ac552fd | 1078 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1079 | |
1080 | struct netlink_set_err_data { | |
1081 | struct sock *exclude_sk; | |
1082 | u32 pid; | |
1083 | u32 group; | |
1084 | int code; | |
1085 | }; | |
1086 | ||
1087 | static inline int do_one_set_err(struct sock *sk, | |
1088 | struct netlink_set_err_data *p) | |
1089 | { | |
1090 | struct netlink_sock *nlk = nlk_sk(sk); | |
1091 | ||
1092 | if (sk == p->exclude_sk) | |
1093 | goto out; | |
1094 | ||
09ad9bc7 | 1095 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1096 | goto out; |
1097 | ||
f7fa9b10 PM |
1098 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1099 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1100 | goto out; |
1101 | ||
1102 | sk->sk_err = p->code; | |
1103 | sk->sk_error_report(sk); | |
1104 | out: | |
1105 | return 0; | |
1106 | } | |
1107 | ||
4843b93c PNA |
1108 | /** |
1109 | * netlink_set_err - report error to broadcast listeners | |
1110 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
1111 | * @pid: the PID of a process that we want to skip (if any) | |
1112 | * @groups: the broadcast group that will notice the error | |
1113 | * @code: error code, must be negative (as usual in kernelspace) | |
1114 | */ | |
1da177e4 LT |
1115 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) |
1116 | { | |
1117 | struct netlink_set_err_data info; | |
1118 | struct hlist_node *node; | |
1119 | struct sock *sk; | |
1120 | ||
1121 | info.exclude_sk = ssk; | |
1122 | info.pid = pid; | |
1123 | info.group = group; | |
4843b93c PNA |
1124 | /* sk->sk_err wants a positive error value */ |
1125 | info.code = -code; | |
1da177e4 LT |
1126 | |
1127 | read_lock(&nl_table_lock); | |
1128 | ||
1129 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1130 | do_one_set_err(sk, &info); | |
1131 | ||
1132 | read_unlock(&nl_table_lock); | |
1133 | } | |
dd5b6ce6 | 1134 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1135 | |
84659eb5 JB |
1136 | /* must be called with netlink table grabbed */ |
1137 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1138 | unsigned int group, | |
1139 | int is_new) | |
1140 | { | |
1141 | int old, new = !!is_new, subscriptions; | |
1142 | ||
1143 | old = test_bit(group - 1, nlk->groups); | |
1144 | subscriptions = nlk->subscriptions - old + new; | |
1145 | if (new) | |
1146 | __set_bit(group - 1, nlk->groups); | |
1147 | else | |
1148 | __clear_bit(group - 1, nlk->groups); | |
1149 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1150 | netlink_update_listeners(&nlk->sk); | |
1151 | } | |
1152 | ||
9a4595bc | 1153 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1154 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1155 | { |
1156 | struct sock *sk = sock->sk; | |
1157 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1158 | unsigned int val = 0; |
1159 | int err; | |
9a4595bc PM |
1160 | |
1161 | if (level != SOL_NETLINK) | |
1162 | return -ENOPROTOOPT; | |
1163 | ||
1164 | if (optlen >= sizeof(int) && | |
eb496534 | 1165 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1166 | return -EFAULT; |
1167 | ||
1168 | switch (optname) { | |
1169 | case NETLINK_PKTINFO: | |
1170 | if (val) | |
1171 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1172 | else | |
1173 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1174 | err = 0; | |
1175 | break; | |
1176 | case NETLINK_ADD_MEMBERSHIP: | |
1177 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1178 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1179 | return -EPERM; | |
b4ff4f04 JB |
1180 | err = netlink_realloc_groups(sk); |
1181 | if (err) | |
1182 | return err; | |
9a4595bc PM |
1183 | if (!val || val - 1 >= nlk->ngroups) |
1184 | return -EINVAL; | |
1185 | netlink_table_grab(); | |
84659eb5 JB |
1186 | netlink_update_socket_mc(nlk, val, |
1187 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1188 | netlink_table_ungrab(); |
1189 | err = 0; | |
1190 | break; | |
1191 | } | |
be0c22a4 PNA |
1192 | case NETLINK_BROADCAST_ERROR: |
1193 | if (val) | |
1194 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1195 | else | |
1196 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1197 | err = 0; | |
1198 | break; | |
38938bfe PNA |
1199 | case NETLINK_NO_ENOBUFS: |
1200 | if (val) { | |
1201 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
1202 | clear_bit(0, &nlk->state); | |
1203 | wake_up_interruptible(&nlk->wait); | |
1204 | } else | |
1205 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; | |
1206 | err = 0; | |
1207 | break; | |
9a4595bc PM |
1208 | default: |
1209 | err = -ENOPROTOOPT; | |
1210 | } | |
1211 | return err; | |
1212 | } | |
1213 | ||
1214 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1215 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1216 | { |
1217 | struct sock *sk = sock->sk; | |
1218 | struct netlink_sock *nlk = nlk_sk(sk); | |
1219 | int len, val, err; | |
1220 | ||
1221 | if (level != SOL_NETLINK) | |
1222 | return -ENOPROTOOPT; | |
1223 | ||
1224 | if (get_user(len, optlen)) | |
1225 | return -EFAULT; | |
1226 | if (len < 0) | |
1227 | return -EINVAL; | |
1228 | ||
1229 | switch (optname) { | |
1230 | case NETLINK_PKTINFO: | |
1231 | if (len < sizeof(int)) | |
1232 | return -EINVAL; | |
1233 | len = sizeof(int); | |
1234 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1235 | if (put_user(len, optlen) || |
1236 | put_user(val, optval)) | |
1237 | return -EFAULT; | |
9a4595bc PM |
1238 | err = 0; |
1239 | break; | |
be0c22a4 PNA |
1240 | case NETLINK_BROADCAST_ERROR: |
1241 | if (len < sizeof(int)) | |
1242 | return -EINVAL; | |
1243 | len = sizeof(int); | |
1244 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1245 | if (put_user(len, optlen) || | |
1246 | put_user(val, optval)) | |
1247 | return -EFAULT; | |
1248 | err = 0; | |
1249 | break; | |
38938bfe PNA |
1250 | case NETLINK_NO_ENOBUFS: |
1251 | if (len < sizeof(int)) | |
1252 | return -EINVAL; | |
1253 | len = sizeof(int); | |
1254 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
1255 | if (put_user(len, optlen) || | |
1256 | put_user(val, optval)) | |
1257 | return -EFAULT; | |
1258 | err = 0; | |
1259 | break; | |
9a4595bc PM |
1260 | default: |
1261 | err = -ENOPROTOOPT; | |
1262 | } | |
1263 | return err; | |
1264 | } | |
1265 | ||
1266 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1267 | { | |
1268 | struct nl_pktinfo info; | |
1269 | ||
1270 | info.group = NETLINK_CB(skb).dst_group; | |
1271 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1272 | } | |
1273 | ||
1da177e4 LT |
1274 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1275 | struct msghdr *msg, size_t len) | |
1276 | { | |
1277 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1278 | struct sock *sk = sock->sk; | |
1279 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1280 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1281 | u32 dst_pid; |
d629b836 | 1282 | u32 dst_group; |
1da177e4 LT |
1283 | struct sk_buff *skb; |
1284 | int err; | |
1285 | struct scm_cookie scm; | |
1286 | ||
1287 | if (msg->msg_flags&MSG_OOB) | |
1288 | return -EOPNOTSUPP; | |
1289 | ||
1290 | if (NULL == siocb->scm) | |
1291 | siocb->scm = &scm; | |
1292 | err = scm_send(sock, msg, siocb->scm); | |
1293 | if (err < 0) | |
1294 | return err; | |
1295 | ||
1296 | if (msg->msg_namelen) { | |
1297 | if (addr->nl_family != AF_NETLINK) | |
1298 | return -EINVAL; | |
1299 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1300 | dst_group = ffs(addr->nl_groups); |
1301 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1302 | return -EPERM; |
1303 | } else { | |
1304 | dst_pid = nlk->dst_pid; | |
d629b836 | 1305 | dst_group = nlk->dst_group; |
1da177e4 LT |
1306 | } |
1307 | ||
1308 | if (!nlk->pid) { | |
1309 | err = netlink_autobind(sock); | |
1310 | if (err) | |
1311 | goto out; | |
1312 | } | |
1313 | ||
1314 | err = -EMSGSIZE; | |
1315 | if (len > sk->sk_sndbuf - 32) | |
1316 | goto out; | |
1317 | err = -ENOBUFS; | |
339bf98f | 1318 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1319 | if (skb == NULL) |
1da177e4 LT |
1320 | goto out; |
1321 | ||
1322 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1323 | NETLINK_CB(skb).dst_group = dst_group; |
0c11b942 | 1324 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current); |
2532386f | 1325 | NETLINK_CB(skb).sessionid = audit_get_sessionid(current); |
0ce784ca | 1326 | security_task_getsecid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1327 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1328 | ||
1329 | /* What can I do? Netlink is asynchronous, so that | |
1330 | we will have to save current capabilities to | |
1331 | check them, when this message will be delivered | |
1332 | to corresponding kernel module. --ANK (980802) | |
1333 | */ | |
1334 | ||
1335 | err = -EFAULT; | |
6ac552fd | 1336 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1337 | kfree_skb(skb); |
1338 | goto out; | |
1339 | } | |
1340 | ||
1341 | err = security_netlink_send(sk, skb); | |
1342 | if (err) { | |
1343 | kfree_skb(skb); | |
1344 | goto out; | |
1345 | } | |
1346 | ||
d629b836 | 1347 | if (dst_group) { |
1da177e4 | 1348 | atomic_inc(&skb->users); |
d629b836 | 1349 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1350 | } |
1351 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1352 | ||
1353 | out: | |
1354 | return err; | |
1355 | } | |
1356 | ||
1357 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1358 | struct msghdr *msg, size_t len, | |
1359 | int flags) | |
1360 | { | |
1361 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1362 | struct scm_cookie scm; | |
1363 | struct sock *sk = sock->sk; | |
1364 | struct netlink_sock *nlk = nlk_sk(sk); | |
1365 | int noblock = flags&MSG_DONTWAIT; | |
1366 | size_t copied; | |
1dacc76d | 1367 | struct sk_buff *skb, *frag __maybe_unused = NULL; |
1da177e4 LT |
1368 | int err; |
1369 | ||
1370 | if (flags&MSG_OOB) | |
1371 | return -EOPNOTSUPP; | |
1372 | ||
1373 | copied = 0; | |
1374 | ||
6ac552fd PM |
1375 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1376 | if (skb == NULL) | |
1da177e4 LT |
1377 | goto out; |
1378 | ||
1dacc76d JB |
1379 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1380 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1381 | bool need_compat = !!(flags & MSG_CMSG_COMPAT); | |
1382 | ||
1383 | /* | |
1384 | * If this skb has a frag_list, then here that means that | |
1385 | * we will have to use the frag_list skb for compat tasks | |
1386 | * and the regular skb for non-compat tasks. | |
1387 | * | |
1388 | * The skb might (and likely will) be cloned, so we can't | |
1389 | * just reset frag_list and go on with things -- we need to | |
1390 | * keep that. For the compat case that's easy -- simply get | |
1391 | * a reference to the compat skb and free the regular one | |
1392 | * including the frag. For the non-compat case, we need to | |
1393 | * avoid sending the frag to the user -- so assign NULL but | |
1394 | * restore it below before freeing the skb. | |
1395 | */ | |
1396 | if (need_compat) { | |
1397 | struct sk_buff *compskb = skb_shinfo(skb)->frag_list; | |
1398 | skb_get(compskb); | |
1399 | kfree_skb(skb); | |
1400 | skb = compskb; | |
1401 | } else { | |
1402 | frag = skb_shinfo(skb)->frag_list; | |
1403 | skb_shinfo(skb)->frag_list = NULL; | |
1404 | } | |
1405 | } | |
1406 | #endif | |
1407 | ||
1da177e4 LT |
1408 | msg->msg_namelen = 0; |
1409 | ||
1410 | copied = skb->len; | |
1411 | if (len < copied) { | |
1412 | msg->msg_flags |= MSG_TRUNC; | |
1413 | copied = len; | |
1414 | } | |
1415 | ||
badff6d0 | 1416 | skb_reset_transport_header(skb); |
1da177e4 LT |
1417 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1418 | ||
1419 | if (msg->msg_name) { | |
6ac552fd | 1420 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1421 | addr->nl_family = AF_NETLINK; |
1422 | addr->nl_pad = 0; | |
1423 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1424 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1425 | msg->msg_namelen = sizeof(*addr); |
1426 | } | |
1427 | ||
cc9a06cd PM |
1428 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1429 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1430 | ||
1da177e4 LT |
1431 | if (NULL == siocb->scm) { |
1432 | memset(&scm, 0, sizeof(scm)); | |
1433 | siocb->scm = &scm; | |
1434 | } | |
1435 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1436 | if (flags & MSG_TRUNC) |
1437 | copied = skb->len; | |
1dacc76d JB |
1438 | |
1439 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES | |
1440 | skb_shinfo(skb)->frag_list = frag; | |
1441 | #endif | |
1442 | ||
1da177e4 LT |
1443 | skb_free_datagram(sk, skb); |
1444 | ||
1445 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1446 | netlink_dump(sk); | |
1447 | ||
1448 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1449 | out: |
1450 | netlink_rcv_wake(sk); | |
1451 | return err ? : copied; | |
1452 | } | |
1453 | ||
1454 | static void netlink_data_ready(struct sock *sk, int len) | |
1455 | { | |
cd40b7d3 | 1456 | BUG(); |
1da177e4 LT |
1457 | } |
1458 | ||
1459 | /* | |
746fac4d | 1460 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1461 | * complete set of kernel non-blocking support for message |
1462 | * queueing. | |
1463 | */ | |
1464 | ||
1465 | struct sock * | |
b4b51029 | 1466 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1467 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1468 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1469 | { |
1470 | struct socket *sock; | |
1471 | struct sock *sk; | |
77247bbb | 1472 | struct netlink_sock *nlk; |
4277a083 | 1473 | unsigned long *listeners = NULL; |
1da177e4 | 1474 | |
fab2caf6 | 1475 | BUG_ON(!nl_table); |
1da177e4 | 1476 | |
6ac552fd | 1477 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1478 | return NULL; |
1479 | ||
1480 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1481 | return NULL; | |
1482 | ||
23fe1866 PE |
1483 | /* |
1484 | * We have to just have a reference on the net from sk, but don't | |
1485 | * get_net it. Besides, we cannot get and then put the net here. | |
1486 | * So we create one inside init_net and the move it to net. | |
1487 | */ | |
1488 | ||
1489 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1490 | goto out_sock_release_nosk; | |
1491 | ||
1492 | sk = sock->sk; | |
edf02087 | 1493 | sk_change_net(sk, net); |
4fdb3bb7 | 1494 | |
4277a083 PM |
1495 | if (groups < 32) |
1496 | groups = 32; | |
1497 | ||
6c04bb18 JB |
1498 | listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head), |
1499 | GFP_KERNEL); | |
4277a083 PM |
1500 | if (!listeners) |
1501 | goto out_sock_release; | |
1502 | ||
1da177e4 LT |
1503 | sk->sk_data_ready = netlink_data_ready; |
1504 | if (input) | |
cd40b7d3 | 1505 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1506 | |
b4b51029 | 1507 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1508 | goto out_sock_release; |
4fdb3bb7 | 1509 | |
77247bbb PM |
1510 | nlk = nlk_sk(sk); |
1511 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1512 | |
4fdb3bb7 | 1513 | netlink_table_grab(); |
b4b51029 EB |
1514 | if (!nl_table[unit].registered) { |
1515 | nl_table[unit].groups = groups; | |
1516 | nl_table[unit].listeners = listeners; | |
1517 | nl_table[unit].cb_mutex = cb_mutex; | |
1518 | nl_table[unit].module = module; | |
1519 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1520 | } else { |
1521 | kfree(listeners); | |
869e58f8 | 1522 | nl_table[unit].registered++; |
b4b51029 | 1523 | } |
4fdb3bb7 | 1524 | netlink_table_ungrab(); |
77247bbb PM |
1525 | return sk; |
1526 | ||
4fdb3bb7 | 1527 | out_sock_release: |
4277a083 | 1528 | kfree(listeners); |
9dfbec1f | 1529 | netlink_kernel_release(sk); |
23fe1866 PE |
1530 | return NULL; |
1531 | ||
1532 | out_sock_release_nosk: | |
4fdb3bb7 | 1533 | sock_release(sock); |
77247bbb | 1534 | return NULL; |
1da177e4 | 1535 | } |
6ac552fd | 1536 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1537 | |
b7c6ba6e DL |
1538 | |
1539 | void | |
1540 | netlink_kernel_release(struct sock *sk) | |
1541 | { | |
edf02087 | 1542 | sk_release_kernel(sk); |
b7c6ba6e DL |
1543 | } |
1544 | EXPORT_SYMBOL(netlink_kernel_release); | |
1545 | ||
1546 | ||
6c04bb18 JB |
1547 | static void netlink_free_old_listeners(struct rcu_head *rcu_head) |
1548 | { | |
1549 | struct listeners_rcu_head *lrh; | |
1550 | ||
1551 | lrh = container_of(rcu_head, struct listeners_rcu_head, rcu_head); | |
1552 | kfree(lrh->ptr); | |
1553 | } | |
1554 | ||
d136f1bd | 1555 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 JB |
1556 | { |
1557 | unsigned long *listeners, *old = NULL; | |
6c04bb18 | 1558 | struct listeners_rcu_head *old_rcu_head; |
b4ff4f04 | 1559 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
1560 | |
1561 | if (groups < 32) | |
1562 | groups = 32; | |
1563 | ||
b4ff4f04 | 1564 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
6c04bb18 JB |
1565 | listeners = kzalloc(NLGRPSZ(groups) + |
1566 | sizeof(struct listeners_rcu_head), | |
1567 | GFP_ATOMIC); | |
d136f1bd JB |
1568 | if (!listeners) |
1569 | return -ENOMEM; | |
b4ff4f04 JB |
1570 | old = tbl->listeners; |
1571 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1572 | rcu_assign_pointer(tbl->listeners, listeners); | |
6c04bb18 JB |
1573 | /* |
1574 | * Free the old memory after an RCU grace period so we | |
1575 | * don't leak it. We use call_rcu() here in order to be | |
1576 | * able to call this function from atomic contexts. The | |
1577 | * allocation of this memory will have reserved enough | |
1578 | * space for struct listeners_rcu_head at the end. | |
1579 | */ | |
1580 | old_rcu_head = (void *)(tbl->listeners + | |
1581 | NLGRPLONGS(tbl->groups)); | |
1582 | old_rcu_head->ptr = old; | |
1583 | call_rcu(&old_rcu_head->rcu_head, netlink_free_old_listeners); | |
b4ff4f04 JB |
1584 | } |
1585 | tbl->groups = groups; | |
1586 | ||
d136f1bd JB |
1587 | return 0; |
1588 | } | |
1589 | ||
1590 | /** | |
1591 | * netlink_change_ngroups - change number of multicast groups | |
1592 | * | |
1593 | * This changes the number of multicast groups that are available | |
1594 | * on a certain netlink family. Note that it is not possible to | |
1595 | * change the number of groups to below 32. Also note that it does | |
1596 | * not implicitly call netlink_clear_multicast_users() when the | |
1597 | * number of groups is reduced. | |
1598 | * | |
1599 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1600 | * @groups: The new number of groups. | |
1601 | */ | |
1602 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1603 | { | |
1604 | int err; | |
1605 | ||
1606 | netlink_table_grab(); | |
1607 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 1608 | netlink_table_ungrab(); |
d136f1bd | 1609 | |
b4ff4f04 JB |
1610 | return err; |
1611 | } | |
b4ff4f04 | 1612 | |
b8273570 JB |
1613 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
1614 | { | |
1615 | struct sock *sk; | |
1616 | struct hlist_node *node; | |
1617 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1618 | ||
1619 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1620 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1621 | } | |
1622 | ||
84659eb5 JB |
1623 | /** |
1624 | * netlink_clear_multicast_users - kick off multicast listeners | |
1625 | * | |
1626 | * This function removes all listeners from the given group. | |
1627 | * @ksk: The kernel netlink socket, as returned by | |
1628 | * netlink_kernel_create(). | |
1629 | * @group: The multicast group to clear. | |
1630 | */ | |
1631 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1632 | { | |
84659eb5 | 1633 | netlink_table_grab(); |
b8273570 | 1634 | __netlink_clear_multicast_users(ksk, group); |
84659eb5 JB |
1635 | netlink_table_ungrab(); |
1636 | } | |
84659eb5 | 1637 | |
1da177e4 | 1638 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1639 | { |
1640 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1641 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1642 | } |
6ac552fd | 1643 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1644 | |
1645 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1646 | { | |
91744f65 | 1647 | kfree_skb(cb->skb); |
1da177e4 LT |
1648 | kfree(cb); |
1649 | } | |
1650 | ||
1651 | /* | |
1652 | * It looks a bit ugly. | |
1653 | * It would be better to create kernel thread. | |
1654 | */ | |
1655 | ||
1656 | static int netlink_dump(struct sock *sk) | |
1657 | { | |
1658 | struct netlink_sock *nlk = nlk_sk(sk); | |
1659 | struct netlink_callback *cb; | |
1660 | struct sk_buff *skb; | |
1661 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1662 | int len, err = -ENOBUFS; |
746fac4d | 1663 | |
1da177e4 LT |
1664 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1665 | if (!skb) | |
bf8b79e4 | 1666 | goto errout; |
1da177e4 | 1667 | |
af65bdfc | 1668 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1669 | |
1670 | cb = nlk->cb; | |
1671 | if (cb == NULL) { | |
bf8b79e4 TG |
1672 | err = -EINVAL; |
1673 | goto errout_skb; | |
1da177e4 LT |
1674 | } |
1675 | ||
1676 | len = cb->dump(skb, cb); | |
1677 | ||
1678 | if (len > 0) { | |
af65bdfc | 1679 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1680 | |
1681 | if (sk_filter(sk, skb)) | |
1682 | kfree_skb(skb); | |
1683 | else { | |
1684 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1685 | sk->sk_data_ready(sk, skb->len); | |
1686 | } | |
1da177e4 LT |
1687 | return 0; |
1688 | } | |
1689 | ||
bf8b79e4 TG |
1690 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1691 | if (!nlh) | |
1692 | goto errout_skb; | |
1693 | ||
1694 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1695 | ||
b1153f29 SH |
1696 | if (sk_filter(sk, skb)) |
1697 | kfree_skb(skb); | |
1698 | else { | |
1699 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1700 | sk->sk_data_ready(sk, skb->len); | |
1701 | } | |
1da177e4 | 1702 | |
a8f74b22 TG |
1703 | if (cb->done) |
1704 | cb->done(cb); | |
1da177e4 | 1705 | nlk->cb = NULL; |
af65bdfc | 1706 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1707 | |
1708 | netlink_destroy_callback(cb); | |
1da177e4 | 1709 | return 0; |
1797754e | 1710 | |
bf8b79e4 | 1711 | errout_skb: |
af65bdfc | 1712 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1713 | kfree_skb(skb); |
1714 | errout: | |
1715 | return err; | |
1da177e4 LT |
1716 | } |
1717 | ||
1718 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
3a6c2b41 | 1719 | const struct nlmsghdr *nlh, |
6ac552fd PM |
1720 | int (*dump)(struct sk_buff *skb, |
1721 | struct netlink_callback *), | |
1722 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1723 | { |
1724 | struct netlink_callback *cb; | |
1725 | struct sock *sk; | |
1726 | struct netlink_sock *nlk; | |
1727 | ||
0da974f4 | 1728 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1729 | if (cb == NULL) |
1730 | return -ENOBUFS; | |
1731 | ||
1da177e4 LT |
1732 | cb->dump = dump; |
1733 | cb->done = done; | |
1734 | cb->nlh = nlh; | |
1735 | atomic_inc(&skb->users); | |
1736 | cb->skb = skb; | |
1737 | ||
3b1e0a65 | 1738 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1739 | if (sk == NULL) { |
1740 | netlink_destroy_callback(cb); | |
1741 | return -ECONNREFUSED; | |
1742 | } | |
1743 | nlk = nlk_sk(sk); | |
3f660d66 | 1744 | /* A dump is in progress... */ |
af65bdfc | 1745 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1746 | if (nlk->cb) { |
af65bdfc | 1747 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1748 | netlink_destroy_callback(cb); |
1749 | sock_put(sk); | |
1750 | return -EBUSY; | |
1751 | } | |
1752 | nlk->cb = cb; | |
af65bdfc | 1753 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1754 | |
1755 | netlink_dump(sk); | |
1756 | sock_put(sk); | |
5c58298c DL |
1757 | |
1758 | /* We successfully started a dump, by returning -EINTR we | |
1759 | * signal not to send ACK even if it was requested. | |
1760 | */ | |
1761 | return -EINTR; | |
1da177e4 | 1762 | } |
6ac552fd | 1763 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1764 | |
1765 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1766 | { | |
1767 | struct sk_buff *skb; | |
1768 | struct nlmsghdr *rep; | |
1769 | struct nlmsgerr *errmsg; | |
339bf98f | 1770 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1771 | |
339bf98f TG |
1772 | /* error messages get the original request appened */ |
1773 | if (err) | |
1774 | payload += nlmsg_len(nlh); | |
1da177e4 | 1775 | |
339bf98f | 1776 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1777 | if (!skb) { |
1778 | struct sock *sk; | |
1779 | ||
3b1e0a65 | 1780 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1781 | in_skb->sk->sk_protocol, |
1da177e4 LT |
1782 | NETLINK_CB(in_skb).pid); |
1783 | if (sk) { | |
1784 | sk->sk_err = ENOBUFS; | |
1785 | sk->sk_error_report(sk); | |
1786 | sock_put(sk); | |
1787 | } | |
1788 | return; | |
1789 | } | |
1790 | ||
1791 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
5dba93ae | 1792 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 1793 | errmsg = nlmsg_data(rep); |
1da177e4 | 1794 | errmsg->error = err; |
bf8b79e4 | 1795 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1796 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1797 | } | |
6ac552fd | 1798 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1799 | |
cd40b7d3 | 1800 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1801 | struct nlmsghdr *)) |
82ace47a | 1802 | { |
82ace47a TG |
1803 | struct nlmsghdr *nlh; |
1804 | int err; | |
1805 | ||
1806 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1807 | int msglen; |
1808 | ||
b529ccf2 | 1809 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1810 | err = 0; |
82ace47a | 1811 | |
ad8e4b75 | 1812 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1813 | return 0; |
1814 | ||
d35b6856 TG |
1815 | /* Only requests are handled by the kernel */ |
1816 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1817 | goto ack; |
45e7ae7f TG |
1818 | |
1819 | /* Skip control messages */ | |
1820 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1821 | goto ack; |
d35b6856 | 1822 | |
1d00a4eb | 1823 | err = cb(skb, nlh); |
5c58298c DL |
1824 | if (err == -EINTR) |
1825 | goto skip; | |
1826 | ||
1827 | ack: | |
d35b6856 | 1828 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1829 | netlink_ack(skb, nlh, err); |
82ace47a | 1830 | |
5c58298c | 1831 | skip: |
6ac552fd | 1832 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1833 | if (msglen > skb->len) |
1834 | msglen = skb->len; | |
1835 | skb_pull(skb, msglen); | |
82ace47a TG |
1836 | } |
1837 | ||
1838 | return 0; | |
1839 | } | |
6ac552fd | 1840 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1841 | |
d387f6ad TG |
1842 | /** |
1843 | * nlmsg_notify - send a notification netlink message | |
1844 | * @sk: netlink socket to use | |
1845 | * @skb: notification message | |
1846 | * @pid: destination netlink pid for reports or 0 | |
1847 | * @group: destination multicast group or 0 | |
1848 | * @report: 1 to report back, 0 to disable | |
1849 | * @flags: allocation flags | |
1850 | */ | |
1851 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1852 | unsigned int group, int report, gfp_t flags) | |
1853 | { | |
1854 | int err = 0; | |
1855 | ||
1856 | if (group) { | |
1857 | int exclude_pid = 0; | |
1858 | ||
1859 | if (report) { | |
1860 | atomic_inc(&skb->users); | |
1861 | exclude_pid = pid; | |
1862 | } | |
1863 | ||
1ce85fe4 PNA |
1864 | /* errors reported via destination sk->sk_err, but propagate |
1865 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
1866 | err = nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
d387f6ad TG |
1867 | } |
1868 | ||
1ce85fe4 PNA |
1869 | if (report) { |
1870 | int err2; | |
1871 | ||
1872 | err2 = nlmsg_unicast(sk, skb, pid); | |
1873 | if (!err || err == -ESRCH) | |
1874 | err = err2; | |
1875 | } | |
d387f6ad TG |
1876 | |
1877 | return err; | |
1878 | } | |
6ac552fd | 1879 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1880 | |
1da177e4 LT |
1881 | #ifdef CONFIG_PROC_FS |
1882 | struct nl_seq_iter { | |
e372c414 | 1883 | struct seq_net_private p; |
1da177e4 LT |
1884 | int link; |
1885 | int hash_idx; | |
1886 | }; | |
1887 | ||
1888 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1889 | { | |
1890 | struct nl_seq_iter *iter = seq->private; | |
1891 | int i, j; | |
1892 | struct sock *s; | |
1893 | struct hlist_node *node; | |
1894 | loff_t off = 0; | |
1895 | ||
6ac552fd | 1896 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1897 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1898 | ||
1899 | for (j = 0; j <= hash->mask; j++) { | |
1900 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1901 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1902 | continue; |
1da177e4 LT |
1903 | if (off == pos) { |
1904 | iter->link = i; | |
1905 | iter->hash_idx = j; | |
1906 | return s; | |
1907 | } | |
1908 | ++off; | |
1909 | } | |
1910 | } | |
1911 | } | |
1912 | return NULL; | |
1913 | } | |
1914 | ||
1915 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1916 | __acquires(nl_table_lock) |
1da177e4 LT |
1917 | { |
1918 | read_lock(&nl_table_lock); | |
1919 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1920 | } | |
1921 | ||
1922 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1923 | { | |
1924 | struct sock *s; | |
1925 | struct nl_seq_iter *iter; | |
1926 | int i, j; | |
1927 | ||
1928 | ++*pos; | |
1929 | ||
1930 | if (v == SEQ_START_TOKEN) | |
1931 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1932 | |
b4b51029 EB |
1933 | iter = seq->private; |
1934 | s = v; | |
1935 | do { | |
1936 | s = sk_next(s); | |
1218854a | 1937 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
1938 | if (s) |
1939 | return s; | |
1940 | ||
1da177e4 LT |
1941 | i = iter->link; |
1942 | j = iter->hash_idx + 1; | |
1943 | ||
1944 | do { | |
1945 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1946 | ||
1947 | for (; j <= hash->mask; j++) { | |
1948 | s = sk_head(&hash->table[j]); | |
1218854a | 1949 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1950 | s = sk_next(s); |
1da177e4 LT |
1951 | if (s) { |
1952 | iter->link = i; | |
1953 | iter->hash_idx = j; | |
1954 | return s; | |
1955 | } | |
1956 | } | |
1957 | ||
1958 | j = 0; | |
1959 | } while (++i < MAX_LINKS); | |
1960 | ||
1961 | return NULL; | |
1962 | } | |
1963 | ||
1964 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1965 | __releases(nl_table_lock) |
1da177e4 LT |
1966 | { |
1967 | read_unlock(&nl_table_lock); | |
1968 | } | |
1969 | ||
1970 | ||
1971 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1972 | { | |
1973 | if (v == SEQ_START_TOKEN) | |
1974 | seq_puts(seq, | |
1975 | "sk Eth Pid Groups " | |
38938bfe | 1976 | "Rmem Wmem Dump Locks Drops\n"); |
1da177e4 LT |
1977 | else { |
1978 | struct sock *s = v; | |
1979 | struct netlink_sock *nlk = nlk_sk(s); | |
1980 | ||
38938bfe | 1981 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %-8d %-8d\n", |
1da177e4 LT |
1982 | s, |
1983 | s->sk_protocol, | |
1984 | nlk->pid, | |
513c2500 | 1985 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
1986 | sk_rmem_alloc_get(s), |
1987 | sk_wmem_alloc_get(s), | |
1da177e4 | 1988 | nlk->cb, |
38938bfe PNA |
1989 | atomic_read(&s->sk_refcnt), |
1990 | atomic_read(&s->sk_drops) | |
1da177e4 LT |
1991 | ); |
1992 | ||
1993 | } | |
1994 | return 0; | |
1995 | } | |
1996 | ||
56b3d975 | 1997 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1998 | .start = netlink_seq_start, |
1999 | .next = netlink_seq_next, | |
2000 | .stop = netlink_seq_stop, | |
2001 | .show = netlink_seq_show, | |
2002 | }; | |
2003 | ||
2004 | ||
2005 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2006 | { | |
e372c414 DL |
2007 | return seq_open_net(inode, file, &netlink_seq_ops, |
2008 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2009 | } |
2010 | ||
da7071d7 | 2011 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2012 | .owner = THIS_MODULE, |
2013 | .open = netlink_seq_open, | |
2014 | .read = seq_read, | |
2015 | .llseek = seq_lseek, | |
e372c414 | 2016 | .release = seq_release_net, |
1da177e4 LT |
2017 | }; |
2018 | ||
2019 | #endif | |
2020 | ||
2021 | int netlink_register_notifier(struct notifier_block *nb) | |
2022 | { | |
e041c683 | 2023 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2024 | } |
6ac552fd | 2025 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2026 | |
2027 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2028 | { | |
e041c683 | 2029 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2030 | } |
6ac552fd | 2031 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2032 | |
90ddc4f0 | 2033 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2034 | .family = PF_NETLINK, |
2035 | .owner = THIS_MODULE, | |
2036 | .release = netlink_release, | |
2037 | .bind = netlink_bind, | |
2038 | .connect = netlink_connect, | |
2039 | .socketpair = sock_no_socketpair, | |
2040 | .accept = sock_no_accept, | |
2041 | .getname = netlink_getname, | |
2042 | .poll = datagram_poll, | |
2043 | .ioctl = sock_no_ioctl, | |
2044 | .listen = sock_no_listen, | |
2045 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2046 | .setsockopt = netlink_setsockopt, |
2047 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2048 | .sendmsg = netlink_sendmsg, |
2049 | .recvmsg = netlink_recvmsg, | |
2050 | .mmap = sock_no_mmap, | |
2051 | .sendpage = sock_no_sendpage, | |
2052 | }; | |
2053 | ||
ec1b4cf7 | 2054 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2055 | .family = PF_NETLINK, |
2056 | .create = netlink_create, | |
2057 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2058 | }; | |
2059 | ||
4665079c | 2060 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2061 | { |
2062 | #ifdef CONFIG_PROC_FS | |
2063 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
2064 | return -ENOMEM; | |
2065 | #endif | |
2066 | return 0; | |
2067 | } | |
2068 | ||
4665079c | 2069 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2070 | { |
2071 | #ifdef CONFIG_PROC_FS | |
2072 | proc_net_remove(net, "netlink"); | |
2073 | #endif | |
2074 | } | |
2075 | ||
022cbae6 | 2076 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2077 | .init = netlink_net_init, |
2078 | .exit = netlink_net_exit, | |
2079 | }; | |
2080 | ||
1da177e4 LT |
2081 | static int __init netlink_proto_init(void) |
2082 | { | |
2083 | struct sk_buff *dummy_skb; | |
2084 | int i; | |
26ff5ddc | 2085 | unsigned long limit; |
1da177e4 LT |
2086 | unsigned int order; |
2087 | int err = proto_register(&netlink_proto, 0); | |
2088 | ||
2089 | if (err != 0) | |
2090 | goto out; | |
2091 | ||
ef047f5e | 2092 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 2093 | |
0da974f4 | 2094 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2095 | if (!nl_table) |
2096 | goto panic; | |
1da177e4 | 2097 | |
4481374c JB |
2098 | if (totalram_pages >= (128 * 1024)) |
2099 | limit = totalram_pages >> (21 - PAGE_SHIFT); | |
1da177e4 | 2100 | else |
4481374c | 2101 | limit = totalram_pages >> (23 - PAGE_SHIFT); |
1da177e4 | 2102 | |
26ff5ddc DC |
2103 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2104 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2105 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2106 | |
2107 | for (i = 0; i < MAX_LINKS; i++) { | |
2108 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
2109 | ||
ea72912c | 2110 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2111 | if (!hash->table) { |
2112 | while (i-- > 0) | |
2113 | nl_pid_hash_free(nl_table[i].hash.table, | |
2114 | 1 * sizeof(*hash->table)); | |
2115 | kfree(nl_table); | |
fab2caf6 | 2116 | goto panic; |
1da177e4 | 2117 | } |
1da177e4 LT |
2118 | hash->max_shift = order; |
2119 | hash->shift = 0; | |
2120 | hash->mask = 0; | |
2121 | hash->rehash_time = jiffies; | |
2122 | } | |
2123 | ||
2124 | sock_register(&netlink_family_ops); | |
b4b51029 | 2125 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2126 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2127 | rtnetlink_init(); |
2128 | out: | |
2129 | return err; | |
fab2caf6 AM |
2130 | panic: |
2131 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2132 | } |
2133 | ||
1da177e4 | 2134 | core_initcall(netlink_proto_init); |